(3av) In Silico Design of Nanoporous Materials for Energy Storage and Environmental Remediation Applications

Confinement of guest phases within the pores of nanostructured materials, such as porous carbons, zeolites and metal-organic frameworks, can signficantly alter phase behavior, chemical equilibria, reaction rates and mechanisms, and transport properties.  In order to develop nanoporous materials with desired performance characteristics, these effects may be finely tuned by modulating the structural features (e.g., porosity, pore size and surface area) of the materials through judicious choice of the precursors and synthesis conditions. As a result, nanoporous materials are playing an increasingly prominent role in the development of many emerging energy- and environment-related technologies, including electric double-layer supercapacitors, membrane systems for water purification and desalination, and adsorbents for CO₂ capture and sequestration.  However, the full potential of these materials has not been realized due to the absence of rational design principles to guide their synthesis and application.  Development of such guidelines for porous materials requires a complete understanding of the relationship between their nanostructure and functional properties.  At present, this level of understanding is difficult to achieve through empirical investigation alone, due to the limited ability of existing experimental techniques to fully resolve the nanoscopic features of these materials and the mechanistic origins of their performance characteristics.

One of my main research interests is to establish a theoretical framework based in statistical mechanics and molecular simulations to assist in the development of rational design principles for nanoporous materials.  These approaches are well-suited for studying phenomena such as adsorption, transport and chemical reactions at the nanoscale, and can provide information that is complementary to experimental measurements and is vital to understanding confinement effects in nanostructured materials.  Specifically, molecular simulation techniques can be used to: (1) resolve the structural features of materials that are challenging to characterize with experiment, (2) elucidate the molecular mechanisms that are responsible for confinement effects, (3) combinatorially screen materials to identify structural features that give rise to enhanced performance attributes, and (4) make quantitative predictions regarding material performance.  As an example, I will discuss the application of molecular simulation techniques to model disordered nanoporous carbons (DNCs), which have gained recent attention due to their exceptional performance as supercapacitor and battery electrode materials.  Although these materials are among the most challenging to experimentally characterize and model due to their amorphous structure, I will demonstrate that simulation methods can be used to help achieve a fundamental understanding of the relationship between the structure and function of DNCs and lay the foundation for establishing rational design principles.